Successful breastfeeding involves a dyadic between a mother a her infant. Studies have consistently demonstrated that certain personal and situational characteristics of the mother are related to quality breastfeeding, yet few studies have examined how infant temperament affects breastfeeding success and continuity. The present study was designed to explore breastfeeding and temperament in infants of depressed mothers and to ascertain whether individual differences in temperament and physiological activity are related to breastfeeding continuity across infancy. We will also examine whether the affective bonding that occurs during infants of depressed mothers. Eight, middle- class, primiparous, adult mothers, 40 of whom will be depressed, and their infants will participate. Additional assessments will be obtained at 1 and 3 months of age. During the neonatal period, mothers will be interviewed for depressive symptoms and breastfeeding intentions. At 1- and 3- months, mothers will respond to interviews, questionnaires related to infant temperament, and will participate in play and feeding interactions. Infants will participate in 4 activities during the 1- and 3- month lab sessions: 1) EEG and ECG recordings; 2) a mildly stressful regulation task; 3) a mother-infant play interaction; and 4) a feeding interaction. Multivariate analyses of variance will be used to examine differences in physiological activity between depressed and non- depressed mothers and infant temperament groups. Using multivariate regression analyses, we will examine whether more positive dyadic interactions are predicted by cessation of maternal depression and breastfeeding continuity across development. These findings will enhance our understanding of the antecedents of breastfeeding in depressed mothers and could provide a foundation for developing intervention techniques directed toward attenuating the affect and physiological dysregulation already noted in infants of depressed mothers.